tekmar 553 Thermostat Installation - Manual (Page 37)

© 2014 553_D - 09/14
37 of 52 A Watts Water Technologies Company
Room Min and Max Limits Section D
Heating and cooling minimum and maximum temperature settings are available in
the Set Temp menu. These allow the installer to select start and stop limits for the
temperature settings in both heating and cooling for the User and Limited access
levels. This is useful in commercial installations and child / guest bedrooms where
availability of the full temperature setting range may not be desirable.
Mode Operation Section E
The thermostat includes a mode key. Available modes are:
Heat - Allows heating
Cool - Allows air and floor cooling
Auto - Automatically switches between heating and cooling as necessary. The
interlock time is applied when switching from heating to cooling or from cooling
to heating. Floor cooling does not operate.
Emergency - Only available when operating a heat pump. When set to
Emergency the heat pump is locked out and the hydronic and backup heat are
operated. •
•
•
•
The thermostat has the option to support floor cooling when connected to a heat pump
control using tekmarNet
® communication. The terminal unit type must be set to be HRF1
or HRF2, the floor cooling setting must be set to On and the heating system must be
in Warm Weather Shut Down (WWSD). When the thermostat is set to Mode Cool, the
floor cooling turns on 1.0°F (0.5°C) below the Set Cool setpoint. This allows the floor
cooling to operate for long periods of time while the air cooling system cycles on and off
to maintain the cooling setpoint. Floor cooling does not operate below 64°F (18.0°C).
Cooling Cold Weather Shut Down ------------------------------------- -------------------------------------
When the outdoor air temperature falls below the Cooling Cold Weather Shut Down
(CWSD) setting on the thermostat, the cooling system is shut off.
Hydronic Pump and Valve Operation Section F
Exercising ---------------------------------------------------------- ----------------------------------------------------------
When connected to a tekmarNet ® system control, the thermostat exercises the heat relay for
10 seconds every 3 days. Exercising helps prevent zone valves or zone pumps from failing
due to precipitate buildup. During exercising, the thermostat shows “TEST” on the display.
Flushing ------------------------------------------------------------ ------------------------------------------------------------
The flushing feature is for open-loop systems that use a domestic hot water tank as a
heat source. Flushing ensures that fresh potable water is circulated through the system
once each day. If the thermostat is connected to a tekmarNet
® system control with the
Flushing feature turned on, the thermostat display will display “FLUSHING” for the
duration of the flushing operation.